Merge pull request #249795 from code-sidd/gipk

Adding GIPK docs

Author: prmerger-automator[bot]

articles/mysql/flexible-server/concepts-data-in-replication.md

@@ -58,6 +58,23 @@ The parameter `replicate_wild_ignore_table` creates a replication filter for tab
 - With **public access**, ensure that the source server has a public IP address, that DNS is publicly accessible, or that the source server has a fully qualified domain name (FQDN).
 - With **private access**, ensure that the source server name can be resolved and is accessible from the VNet where the Azure Database for MySQL instance is running. (For more details, visit [Name resolution for resources in Azure virtual networks](../../virtual-network/virtual-networks-name-resolution-for-vms-and-role-instances.md)).
 
+### Generated Invisible Primary Key
+
+For MySQL version 8.0 and above, [Generated Invisible Primary Keys](https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html)(GIPK) is enabled by default for all the Azure Database for MySQL Flexible Servers. MySQL 8.0+ servers adds the invisible column *my_row_id* to the tables and a primary key on that column, where the InnoDB table is created without an explicit primary key. This feature, when enabled may impact some of the data-in replication use cases, as described below:
+
+- Data-in replication fails with replication error: “**ERROR 1068 (42000): Multiple primary key defined**” if source server creates a Primary key on the table without Primary Key. For mitigation, run the following sql command, skip replication error and restart [data-in replication](how-to-data-in-replication.md). 
+
+   ```sql
+   alter table <table name> drop column my_row_id, add primary key <primary key name>(<column name>);
+   ```
+
+- Data-in replication fails with replication error: "**ERROR 1075 (42000): Incorrect table definition; there can be only one auto column and it must be defined as a key**" if source server adds an auto_increment column as Unique Key. For mitigation, run the following sql command, set "[sql_generate_invisible_primary_key](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_sql_generate_invisible_primary_key)" as OFF, skip replication error and restart [data-in replication](how-to-data-in-replication.md).
+   ```sql
+   alter table <table name> drop column my_row_id, modify <column name> int auto_increment;
+   ```
+
+- Data-in replication fails if source server runs any other SQL that isn't supported when "[sql_generate_invisible_primary_key](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_sql_generate_invisible_primary_key)" is ON. For example, create a partition table. In such a scenario mitigation is to set "[sql_generate_invisible_primary_key](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_sql_generate_invisible_primary_key)" as OFF and restart [data-in replication](how-to-data-in-replication.md). 
+
 ## Next steps
 
 - Learn more on how to [set up data-in replication](how-to-data-in-replication.md)

articles/mysql/flexible-server/concepts-limitations.md

@@ -24,6 +24,21 @@ This article describes limitations in the Azure Database for MySQL - Flexible Se
 
 Azure Database for MySQL supports tuning the values of server parameters. Some parameters' min and max values (ex. `max_connections`, `join_buffer_size`, `query_cache_size`) are determined by the compute tier and before you compute the size of the server. Refer to [server parameters](./concepts-server-parameters.md) for more information about these limits.
 
+### Generated Invisible Primary Keys
+For MySQL version 8.0 and above, [Generated Invisible Primary Keys](https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html)(GIPK) is enabled by default for all the Azure Database for MySQL Flexible Servers. MySQL 8.0+ servers adds the invisible column *my_row_id* to the tables and a primary key on that column, where the InnoDB table is created without an explicit primary key. For this reason, you can't create a table having a column named *my_row_id* unless the table creation statement also specifies an explicit primary key,[Learn more](https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html).
+By default, GIPKs are shown in the output of [SHOW CREATE TABLE](https://dev.mysql.com/doc/refman/8.0/en/show-create-table.html), [SHOW COLUMNS](https://dev.mysql.com/doc/refman/8.0/en/show-columns.html), and [SHOW INDEX](https://dev.mysql.com/doc/refman/8.0/en/show-index.html), and are visible in the Information Schema [COLUMNS](https://dev.mysql.com/doc/refman/8.0/en/information-schema-columns-table.html) and [STATISTICS](https://dev.mysql.com/doc/refman/8.0/en/information-schema-statistics-table.html) tables.
+For more details on GIPK and its use cases with [Data-in-Replication](./concepts-data-in-replication.md) in Azure Database for MySQL Flexible Server, refer [GIPK with Data-in-Replication](./concepts-data-in-replication.md#generated-invisible-primary-key). 
+
+#### Steps to disable GIPK
+
+- You can update the value of server parameter [sql_generate_invisible_primary_key](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_sql_generate_invisible_primary_key) to 'OFF' by following steps mentioned on how to update any server parameter from [Azure portal](./how-to-configure-server-parameters-portal.md#configure-server-parameters) or by using [Azure CLI](./how-to-configure-server-parameters-cli.md#modify-a-server-parameter-value). 
+
+- Or you can connect to your Azure Database for MySQL Flexible Servers and run the below command.
+```sql
+mysql> SET sql_generate_invisible_primary_key=OFF;
+```
+
+
 ## Storage engines
 
 MySQL supports many storage engines. On Azure Database for MySQL - Flexible Server, the following is the list of supported and unsupported storage engines:
@@ -80,7 +95,7 @@ The following are unsupported:
 
 ### Network
 
-- Connectivity method can't be changed after creating the server. If the server is created with *Private access (VNet Integration)*, it can't be changed to *Public access (allowed IP addresses)* after creation, and vice versa
+- Connectivity method can't be changed after creating the server. If the server is created with *Private access (virtual network Integration)*, it can't be changed to *Public access (allowed IP addresses)* after creation, and vice versa
 
 ### Stop/start operation
 

articles/mysql/flexible-server/whats-new.md

@@ -31,8 +31,8 @@ This article summarizes new releases and features in Azure Database for MySQL -
 Universal Geo Restore feature will allow you to restore a source server instance to an alternate region from the list of Azure supported regions where flexible server is [available](./overview.md#azure-regions). If a large-scale incident in a region results in unavailability of database application, then you can use this feature as a disaster recovery option to restore the server to an Azure supported target region, which is different than the source server region. [Learn more](concepts-backup-restore.md#restore)
 
 - **Generated Invisible Primary Key in Azure Database for MySQL - Flexible Server** 
-Azure Database for MySQL Flexible Server now supports generated invisible primary key (GIPK) mode for MySQL version 8.0. With this change, by default, the value of the server system variable "sql_generate_invisible_primary_key" is ON for all MySQL - Flexible Server on MySQL 8.0. With GIPK mode ON, MySQL generates an invisible primary key to any InnoDB table which is new created without an explicit primary key. Learn more about the GIPK mode:
-[Generated Invisible Primary Keys](https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html)
+Azure Database for MySQL Flexible Server now supports [generated invisible primary key (GIPK)](https://dev.mysql.com/doc/refman/8.0/en/create-table-gipks.html) for MySQL version 8.0. With this change, by default, the value of the server system variable "[sql_generate_invisible_primary_key](https://dev.mysql.com/doc/refman/8.0/en/server-system-variables.html#sysvar_sql_generate_invisible_primary_key) " is ON for all MySQL - Flexible Server on MySQL 8.0. With GIPK mode ON, MySQL generates an invisible primary key to any InnoDB table which is new created without an explicit primary key. Learn more about the GIPK mode:
+[Generated Invisible Primary Keys](./concepts-limitations.md#generated-invisible-primary-keys)
 [Invisible Column Metadata](https://dev.mysql.com/doc/refman/8.0/en/invisible-columns.html#invisible-column-metadata)
 
 ## July 2023